Currently there are several standard ways to access or send email messages, and current methods use a network mailbox, to which a client device logs on for access. Example protocols include POP, IMAP and SMTP. There are also several proprietary protocols in use.
Generally, email messages are stored in a storage server, to which the intended receiver logs on to retrieve or access them. POP and IMAP allow a user to view a message whilst it is located in the message store. SMTP is a protocol for sending e-mail messages.
Throughout the current art, the email access procedure is the same no matter what kind of end terminal accesses the mail and no matter what the current networking capacity or link capacity. Nevertheless, the downloading terminal may be any one of a range of terminals connected over any kind of link and may range from a cellular telephone connected over a bandwidth-limited cellular network to a personal organizer or PDA to a desktop computer connected over a high bandwidth digital link.
Generally, most terminals are capable of handling and displaying a certain amount of textual content. However not all terminals are suitable for the file sizes needed to display even a moderate length e-mail message. Often, as with a mobile telephone, the lack of suitability is due to the terminal's limited display size, unwieldy user interface and lack of sufficient memory.
Most terminals are capable of transferring e-mail messages within a reasonable time frame, and mobile terminals can also achieve reasonable performance as long as the message is purely text. Problems arise when files, such as word processing documents of considerable size or multimedia files, are attached to e-mail messages. In addition, displaying or playing multimedia files on mobile devices pose problems due to the lack or insufficiency of appropriate device resources. Multimedia files may require format and dimension conversion in order to be successfully played on a mobile device. For example, typical cellular telephones have very little capacity to handle multimedia files, and bandwidth limited links may be unable to transfer such files in a reasonable amount of time. Furthermore, the kinds of multimedia files that cellular telephones are able to handle are limited in any case. The mobile device may also have limited storage and display capabilities. Additionally, the device may not always have the required software to display all of the content types within a message (e.g. a Powerpoint™ presentation requires a Powerpoint™ “player”). Furthermore, the basic protocols in use, such as IMAP & POP protocols, cannot provide information about the capacity of a link or a receiving terminal. Limitations in storage capacity at the receiving terminal may, for example, make it difficult to download data for subsequent offline viewing. However, both IMAP and POP deliver an exact copy of the stored message, regardless of the receiving device or link capacity.
Further difficulties with the current art may include requiring a socket connection to be kept open for the duration of a session. The IMAP and POP protocols usually download an entire message, i.e. the e-mail text, as a single block, although attachments may be downloaded separately.
In many cases, a user logs on, establishes a socket connection, downloads material related to a first e-mail message, then spends the next few seconds or minutes reading the material before she/he attempts a second download. Because the user does not log off while reading the material from the first e-mail message, the socket connection remains open, albeit inactive, and network connection resources are, therefore, wasted. If the socket connection is ended, then the session ends and the user is required to log on again and may need to repeat certain steps in order to resume operation from the previous, ended, session. This poses an inconvenience to the user, because some or all of the session operations must be repeated. Furthermore, current e-mail architectures, such as IMAP & POP, make it difficult to perform any form or processing on the e-mail message prior to its arrival at the recipient. For example it is difficult to arrange the e-mail to accord with requirements set by the recipient, for example text to speech or language translation. A reason for this is that the mail protocol level does not allow for any recognition of the end user except as an address that pulls the message.